In the following discussion certain articles and methods will be described for background and introductory purposes. Nothing contained herein is to be construed as an “admission” of prior art. Applicant expressly reserves the right to demonstrate, where appropriate, that the articles and methods referenced herein do not constitute prior art under the applicable statutory provisions.
Synthetic biology is a promising new field at the interface of engineering and biology. For review, see e.g., Endy D, Science. 2008 Feb. 29; 319(5867):1196-7. Recently parallel methods have been used to synthesize many different DNA sequences simultaneously, and to provide them as a pool of oligonucleotides. These and other effective methods for synthesizing relatively small pieces of DNA, typically up to a few kilobases in size, allow cost-effective production of large amounts of these oligonucleotides. With the availability of these high-quality, low-cost nucleic acid building blocks, much larger segments of DNA have been constructed. To date, these oligonucleotides have been used in the construction of an entire genome, the Mycoplasma genitalium genome, which is 583 kb (Gibson D G et al., PNAS USA. 2008 Dec. 23; 105(51):20404-9. Epub 2008 Dec. 10.)
Despite these advances, construction of multi-kilobase scale DNA molecules remains difficult and costly, largely because that de novo chemical synthesis of the DNA building blocks is quite error-prone. The intrinsic error rate of solid-phase oligo synthesis is thus a major limitation in the cost-effective assembly of larger DNA molecules. In addition, amplification steps that are used to increase the amount of starting material may also introduce errors, and certain large-scale oligonucleotide production methods may have an additional source of errors. Techniques required to identify and select oligonucleotides that are error-free—such as gel purification, bacterial vector cloning, comprehensive DNA sequencing, and enzymatic methods—are typically quite involved and not cost effective for wide-scale use in synthetic biology.
There remains a need to select error-free synthesized oligonucleotides for use in synthetic biology and other analytical methods. The present invention addresses this need by providing constructs, sets of constructs, and methods for ensuring accuracy of oligonucleotides having a desired sequence.